The present invention relates to an image recording apparatus particularly used as a copying apparatus, and more particularly to a composite image-reproducible copying apparatus having an image composing device capable of composing a trimmed image and a masking image into a composite image.
The present invention relates also to a copying apparatus capable of copying an additional information such as a date along with an original document information simultaneously.
For example, an electronic copying apparatus of the electrophotographic process is an apparatus in which the photoreceptor drum thereof is charged and exposed to the light reflected from an original document information, and the electrostatic latent image formed on the drum surface is developed by a toner into a visible toner image, which is then transferred onto a sheet of recording paper. Electronic copying apparatus of this type has lately been extensively used for copying information in all industrial fields. And most of the latest electronic copying apparatus has a zooming function for enlargement/reduction copying of images in addition to the function of automatically making a set number of copies.
Further, recently, electronic copying apparatus equipped with an autodating function besides the above functions has made its appearance. Electronic copying apparatus of this type has a date display section such as of liquid crystal underneath its document glass plate's scale plate so that the date display image can be copied along with document information.
FIG. 21 is a drawing showing the construction of conventional electronic copying apparatus of this type. If an operator depresses the copying start button (not shown), the apparatus shown in the drawing then starts its copying operation. A photoreceptor drum 201 that revolves in the direction of the arrow, after the residual toner on the drum is scraped off by a blade at a cleaning section 202, is overall subjected to corona discharge by a charging electrode 203, whereby the entire surface of the drum is positively charged. Unnecessary parts of the charge on the drum surface charged by electrode 203 are eliminated by an eliminating lamp 204. After that, the charged surface area of drum 201 is exposed to an imagewise light signal, and an electrostatic latent image corresponding to an original document image is then formed on the drum surface. The electrostatic latent image formed on the drum surface is then developed by a toner at the following developing section 205 into a visible image. The toner image on the drum surface is transferred onto a sheet of recording paper in transfer section 206, and the recording paper in close contact with drum 201 is then separated. The separated recording paper is transported through a transport mechanism 207 to juxtaposed rollers 208 thereby be heated and pressed, whereby the toner on the recording paper is fused, and thus a cycle of copying operation is completed. Further, electronic copying apparatus capable of partially trimming and masking the area of a document image also has lately made its appearance wherein the term `trimming` means leaving intact only the inside of a boundary line with the other part being eliminated. while the term 1 masking` means erasing only the inside of a boundary line with the other part being left intact. FIG. 22 is a drawing showing a conventional example of apparatus of this type. In the drawing, 211 is a glass document plate, 212 is an original document placed on the glass document plate 212, and 213 is an objective boundary line defining an area to be trimmed or masking. 214 is a keyboard comprised of display section 215, ten-key array 216 and function key 217.
Where the objective boundary line 213 is a simple rectangle as shown in the figure, if the positions of two points (e.g., points A and C) on an arbitrary diagonal of the four corners A, B, C and D are known, then an objective boundary line 213 can be specified. The coordinates of point A are now regarded as (X.sub.1, Y.sub.1), and those of point C as (X.sub.2, Y.sub.2). The values of X.sub.1, X.sub.2, Y.sub.1 and Y.sub.2 are read from the graduations on X and Y axes.
The operator revises the trimming or masking mode by using function key 217, and after that first makes an input of coordinate data of X.sub.1 (e.g., 20, 5 as shown in the drawing) by the ten-key array in accordance with the indication of display section 215, and then takes them into the internal control circuit (not shown) by function key 217. Subsequently, the operator feeds in the coordinate data of X.sub.2 in the same way. After completion of the input of the positional coordinate data on the X axis, the operator feeds in the positional coordinate data Y.sub.1, Y.sub.2 on the Y axis in the same way. When a document image is copied after an objective area is thus specified, a trimmed image as shown in FIG. 23(a) or a masking image as shown in (b) can be obtained. An attempt has lately been made to utilize electronic copying apparatus of this type to compose a trimmed image and a masking image into one copy image. Such an image composition is effective in obtaining a multicolor composite image as shown in FIG. 24 by composing, for example, a trimmed image 221 as shown in FIG. 23(a) and a masking image 222 as shown in (b), which images are differentiated in color (e.g., image 221 is colored red and image 222 blue).
In the case of such an image composition, even how accurately the trimming area and the masking area are specified and even if the positive or negative charge on the uniformly charged drum surface is eliminated by being exposed to light, two different images are seldom composed in a proper position as is shown in FIG. 24 by reason of the irradiation caused by the width of the light beam, the timing delay of the electronic circuit inside electronic copying apparatus, or the dislocation of an original document the copying operation, and therefore in most cases there occurs an overlap as shown in FIG. 25. Namely, an overlappedly printed portion 223 as in the drawing appears to degrade the quality of a copy image.
Additional information recorder-equipped electronic copying apparatus of this type is so designed as to quickly feed a sheet of copying paper to copy the image of additional information display section 231 such as of a date in the leading end (heading) area of the paper before copying the text image of document information. In this instance, the liquid crystal display section for additional information is usually provided underneath the document glass plate's scale plate, but because the reflectivities of the liquid crystal display plane and the reverse of the scale plate usually differ, if copying is made without taking a proper measure such as eliminating the charge in the non-additional information display area 233 by means of charge eliminating section 204 (see FIG. 22), a fog is produced between the additional information display section area and the other area, thus degrading the copy image quality. In the case where an additional information such as a date by autodating system is recorded using the indication of the additional information display section provided to the glass document plate, the copy image quality can be improved by eliminating by means of charge eliminator 204 the periphery of the display image area of the display section, while in the case of magnification-variable copying such as enlargement/reduction copying, the display image area also varies according to variation of the magnification. Accordingly, if the charge eliminating area is invariable when varying the magnification, there occurs an unfavorable phenomenon such as the appearance of an undesirable pattern at the periphery of the display area (in reduction copying) or partial missing in the display image by being partially eliminated by the charge eliminator (in enlargement copying).